1. Field of the Invention
This invention relates to surgical instruments which provide a conduit to a body cavity to be treated and, more particularly, to instruments which provide a conduit for admitting gas, fiberoptic cameras and long handled surgical instruments into the abdominal cavity.
With improvements in medical technology and fiberoptics, surgical procedures requiring minimal incisions into the patient have become commonplace. In laparoscopic surgical procedures, it is now common to inflate the abdomen with gas, preferably carbon dioxide, in order to provide better vision of the organ or tissue to be treated as well as to provide more room for manipulation of the surgical instruments. As a result, surgical procedures which previously required opening of the abdomen with a large incision can now be performed through puncture holes. These improved techniques have a wide application in gynecological surgery and most recently in biliary tract, or gall bladder, surgery. When smaller incisions are used, the patient's risks of developing post-operative complications, such as bleeding, infection or hernia formation, are reduced. Additionally, shorter hospital stays are required. Good vision and maintained inflation of the abdomen are the keys to performing a successful surgical procedure in accordance with this method.
2. Description of the Prior Art
U.S. Patent No. 3,817,251 to Hasson discloses a laparoscope cannula which includes an adjustable coneshaped sleeve for blocking the incisional gap and maintaining the inflation of the abdominal cavity. Note that the cannula also includes a pair of hooks for receiving a suture to maintain the cannula in place with respect to the patient's abdomen.
U.S. Pat. No. 3,046,988 to Moreau et al. discloses an esophageal nasogastric tube having a nasal cuff made from plastic sponge which is slideably mounted onto the proximal end of a tube. The distal end of the tube includes a balloon which inflates inside of the stomach to hold the tube in proper position and prevent it from coming out of the stomach.
U.S. Pat. No. 2,936,760 to Gants discloses a positive pressure catheter having a balloon slideably mounted on the catheter tube at the proximal end with a relatively stationary balloon at the distal end for insertion and inflation within the bladder. The slideable balloon is then drawn tight against the patient to maintain the catheter in the desired position. U.S. Pat. No. 2,687,131 to Raiche discloses a catheter of similar design. Other well-known catheters include a balloon inflatable within the stomach and a flange which must be sutured to the skin outside the abdominal wall to hold the catheter in place.
FIGS. 1 and 2 show the instrumentation which is currently available for creating a port in the abdominal wall to admit fiberoptic cameras and long handled instruments into the abdominal cavity. A laparoscopic trocar A having a port sleeve B is inserted through the abdominal wall. The surgeon then releases the trocar A from the sleeve B by depressing a pair of spring-loaded tabs C and pulling trocar A from the sleeve B. Each tab C includes a tongue D at its downward end to secure the handle of trocar A to the handle of sleeve B.
FIG. 2 shows the trocar A after removal from the sleeve B. Trocar A includes a shaft E and a pyramid blade F, which are received by sleeve B in a telescoping manner. Trocar A also includes a safety sheath G which covers blade F and which extends the full length of shaft E. The safety sheath G is spring-loaded to retract within the handle of trocar A. Retraction of safety sheath G is controlled by a sheath trip H located on the bottom of the trocar handle. When sheath trip H is depressed, the safety sheath G is unlocked, and the sheath is then retractable.
Once the trocar A is removed from sleeve B, after insertion into the abdomen, a conduit for admitting gas and surgical instruments to the abdominal cavity is created. Sleeve B includes a flap valve I which is biased in the closed position for maintaining inflation within the abdominal cavity after gas has been pumped therein. Flap valve I may be opened for admittance of surgical instruments through sleeve B.
Two major problems exist with prior art sleeve B. First, inflation gas escapes from the abdominal cavity around the sleeve B and adjacent tissue when the sleeve is manipulated by the surgeon to move the camera and the instruments during the operation. Secondly, it is difficult to maintain the proper depth of insertion of sleeve B through the abdominal wall, resulting in inadvertent withdrawal of sleeve B from the puncture incision. This delays the operation because the sleeve must be reinserted in the puncture and additional inflation gas must be admitted into the abdomen. To prevent such problems, the surgeon must keep one of his hands on sleeve B to maintain the sleeve in the proper position. This hand could be more efficiently used in steering the operating instruments.
It is, therefore, an object of the present invention to provide a trocar with a sleeve that may be fixed on the abdominal wall without the need to hold the sleeve in place. It is a further object to provide an air-tight seal around the puncture incision so that inflation of the abdominal cavity is maintained for optimal visibility and easier instrument manipulation.